Adprep was unable to check the version of the operating system on the Schema FSMO %1. Status/Consequence Adprep has stopped ...

Adprep was unable to check the version of the operating system on the Schema FSMO %1.
[Status/Consequence]
Adprep has stopped without making changes. The version check is critical when the forest is prepared.
[User Action]
Check the log file ADPrep.log in the %2 directory for possible cause of failure.